In recent years, various electronic components have been proposed and are put in practical use, and increasingly high performance has been required on such components. In particular, electric components are required for maintaining performance for a long period of time even under severe environment. The same applies for semiconductor devices such as memory modules and light emitting diodes (LEDs). Requirements for higher performance in the area of general lighting, in-vehicle lighting, and the like, further higher output (higher luminance) and higher reliability are demanded. Accordingly, for example, JP H05-102386A proposes the use of a clad material having a stacked-layer structure formed by pressure bonding, for a lead frame material that has a high degree of hardness and a high electrical conductivity.
Also, depending on the usage of the semiconductor device, further reduction in size of the electric components while retaining the high performance has been demanded. Accordingly, various adjustments have been made in the structure of the package as well as in the structure of the semiconductor element.
For example, in a semiconductor device capable of further reducing the thickness, a provision of irregular shape on the opposing end surfaces of the die pads and the lead portions is proposed to obtain adhesion of the semiconductor element with the sealing resin and the leads (for example, JP2011-151069A etc.).